MINOR: epoll: move epoll_fd to read_mostly
This one only contains the list of per-thread epoll FDs, and is used
a lot during updates. Let's mark it read_mostly to avoid false sharing
of FDs placed at the extremities.
diff --git a/src/ev_epoll.c b/src/ev_epoll.c
index 506805f..330c38c 100644
--- a/src/ev_epoll.c
+++ b/src/ev_epoll.c
@@ -26,7 +26,7 @@
/* private data */
static THREAD_LOCAL struct epoll_event *epoll_events = NULL;
-static int epoll_fd[MAX_THREADS]; // per-thread epoll_fd
+static int epoll_fd[MAX_THREADS] __read_mostly; // per-thread epoll_fd
#ifndef EPOLLRDHUP
/* EPOLLRDHUP was defined late in libc, and it appeared in kernel 2.6.17 */